1) Field of the Invention
The present invention relates to a control device for soft starting and protecting overload of a motor, and more particularly to a control device for soft starting and protecting overload of a motor in a power tool capable of reducing the risk of physical damage to user's hand caused by a torque reaction.
2) Description of the Related Art
With rapid development of industrial technology, manual labors are gradually being replaced by power tools. However, the safety of using power tools is a concern. Since the rotation speed of the power-driven motor varies abruptly in a short time and the large current generates start torque when the motor is started, the user who holds the power tool may react intuitively. For example, for a user who uses a hand-held grinder, he will hold the tool firmly to prevent the tool from flying away when the power tool is started.
Further, the main deficiency of the power tool stated above is that, when the power tool is started, there exists risk of physical damage to the hand of user caused by the starting torque. Besides, although there are table-top power tools that are fixed on the table to ameliorate damage to the user's, such tools still have problems of strong vibration and power consumption.
In view of the deficiencies of power tool mentioned above, the present inventor proposes a control device for soft starting and overload protection of motor in a power tool such that the safety and convenience of using power tool is ensured.